Armor rod



Oct. 19, 1954 T. F. PETERSON 2,691,865

ARMOR ROD iled Nov. 8, 1948 2 Sheets-Sheet 1 FIG. 8 F|G.9 FiG.

8 FIG. 3

I g wohom) Loy ATTORNEY Oct. 19, 1954 T. F. PETERSON 2,691,865

ARMOR ROD iled Nov. 8, 1948 2 Sheets-Sheet 2 3mm THOMAS F. PETERSON,

ATTOR N EY Patented Oct. 19, 1954 UNITED STATS OFFICE ARMOR ROD Application November 8, 1948, Serial No. 58,989

14 Claims.

This invention relates to preformed helical reinforcements commonly referred to as Armor Rods of the kind disclosed in my copending ap plications Serial No. 601,245, filed June 23, 1945, now Patent No. 2,587,521; Serial No. 698,312, filed September 20, 1946; Serial No. 2,200, filed January 14, 1948 and Serial No. 23,579, filed April 27, 1948, now Patent No. 2,609,653.

In its usual form the invention appears as round rod or wire stock to which is imparted a helical set for the purpose of embracing suspended line wires in gripping relation. The armor rods may, however, be composed of substances other than metal, such as plastics, etc., and may take other cross-sectional configurations than round, although round metal sections are the preferred form.

This invention is especially concerned with the shearing of uncut lengths of preformed helices in such a manner that the burr or flash which results from the drag of metal between the sheared sections is disposed so that it can not scratch or cut the surface of a line wire or conductor about which it is to be disposed. It is the aim of this invention to teach how this may be done without additional peening, forming or shaping of the ends of the wire or rod to eliminate this objectionable sharp projection of metal.

It is accordingly the primary object of this invention to teach a preferred manner of shearing armor rods into cut lengths so that the attendant sheared edges are oriented in a preferred way to prevent the harmful effects noted above without special or additional handling or processing. It is a further objective to provide a new sheared product having these characteristics.

These and other objects and advantages will become apparent hereinafter when the specification is considered in conjunction with the accompanying drawings in which:

Figure 1 is a schematic side elevational view of a conventional shearing operation on armor rod stock. Figure 2 is an end view of Figure 1 regarded from its right side.

Figures 3 and 4 are fragmentary side and end views, respectively, of the sheared ends of a helix cut in accordance with the conventional practice.

Figures 5 and 5A are perspective views of the effects, respectively, of the conventionally cut ends of armor rods upon a conductor or cable about which they are wrapped, and those formed in accordance with the present invention.

Figures 6 and '7 are an end view and fragmentary side elevational views, respectively, of armor rods sheared in accordance with the present in vention. 1 v

Figures 8 and 9 are, respectively, plan views of sections of right and left lay preformed helical stock, showing the presentation of the latter to shears in accordance with the present invention, illustrating the considerations attendant thereupon in a schematic manner, while Figures 8a and Qa'are, respectively, end views of the armor rods of Figures 8 and 9, to which diagrams have been added.

Figure 10 is a schematic side elevational view of apparatus arranged in a preferred relationship to give effect to the present invention.

Figure 11 is an enlarged fragmentary elevational View of part of the apparatus shown in Figure 10.

Figure 12 is a perspective view of a mandrel element contained in the assembly of Figure 11, while Figure 13 is a sectional view taken along line I3-l3 of Figure 11.

Referring now more particularly to the drawings, in which like characters of reference refer to corresponding parts throughout, armor rods it, when sheared in-accordance with the conventional practice, illustrated in Figures 1 and 2, tend to roll under the advance of the shear blade i2 until the point of initial contact is forced against the complementary shearing member iii. If the armor rod is disposed in a horizontal position, and the axis of shear is vertical, the point of shear will occur at the nadir n of the helix regarded along its axis as in Figure 2, and the aXis of shear indicated at 7c in Figures 1 and 2, will coincide with the vertical radii of the helix, and will pass diametrically therethrough as indicated in these figures.

As is inherent in most shearing operations, relative displacement of metal between sections that are severed in shear cause eccentric fins or drag upon the sheared ends of the two sections as shown at l5, id in Figures 3 and 4. Regarding the conventionally cut helix in an end view as shown in Figure 4, the fin l5 extends inwardly of the helix It at one of its ends, and extends outwardly of the helix at its opposite end, as appears at l5 in Figure 4. Thus, the long axis of the cut section is disposed radially of the helix as shown at I311 of this figure and the sharp projection is so disposed as to mark or scratch the underlying wire W as at it in Figure 5. This marking is aggravated by virtue of the stiff nature of the wire of which armor rods are made, combined with the shortening effect, and hence diminishing resilience, of the end of the armor rod as it is twisted into place upon a wire W, until finally the sharp projection l 5 at the end of the rod bears forcefully against the wire seriously to mark it. This not only impairs the integrity of protective coatings, but has the even more serious effect of providing a notch point in the wire for the concentration of stresses, which can lead to the early failure of a wire at such point when in operative position.

It has been proposed to peen over the ends of such fins as result from shearing with the effect that the cost of armor rods has been materially increased and the handling and inconvenience which this has entailed have all combined to make this practice undesirable.

In accordance herewith, armor rods, as shown in Figure 6, are sheared so that the axis of shear l 3a is disposed tangentially to the axis of the wire indicated at X in Figure 6. In this manner the fiash or fins I5, I 5 are disposed at both ends of a cut helix in a direction in which they can do no harm to line bodies to which the helix is ultimately applied, with the one added condition, however, that the out be made with respect to the relative motion of the shearing elements so that the flash or fin will extend relatively to the left (arrow 21, Fig. 7) regarding th lead end of a right hand lay helix HER, and relatively to the right (Zr) in the case of a left hand lay helix, L, and vice versa with respect to the trailing ends of each. (See arrows tr and ti, respectively, in these figures.)

This will be more fully understood by referring to Figures 8, 8a, 9, 9a in the ensuing description. I-Iere identical sections of a right lay 10R, (Figure 8), and a left lay [0L (Figure 9) armor rod are shown. The top of these figures represents the lead ends of these armor rods, respectively, as they emerge from a forming machine. The shearing has been shown in several positions the better to illustrate the considerations attendant upon disposing the fiash or fin in a direction in which it will be harmless in the use of such rods. These, for simplicity of illustration, have been combined in the several positions A to D, respectively in these views.

The thread of the external circumference of each helix lies within the surface of a cylinder EC, and the thread of the internal circumference of each helix lies within a cylinder IC, while the axis X of the wire composing each helix corresponds to points within an intermediate cylinder H as seen in these figures. In accordance with this teaching, the effective elements of the shear blades S, S which actually engage and sever the wire must move between parallel planes IT, ET, IT, ET, respectively, which are tangent to the internal and external cylinders 10, EC of the helices, respectively, so that the axis is of the shearing operation falls tangent to the cylinder H of the axis X of the component wire, and so that the plane of shear falls substantially normal to the latter axis. Further considerations require that the drag or fin of metal project leftwardly in the case of the right lay helix,and rightwardly in the case of the left lay helix, the lead end. of each being regarded in elevational plan view in each case.

Thus in Figures 8 and 9, the shear blades S, S at station A are such that the flash of the lead end will be disposed downwardly as shown by the arrow is in Figure 8a, and upwardly as shown by k in Figure 9a at A. In the case of right hand lays, and with the relationship of parts shown in these figures, one shear blade S is moved toward the eye at station A, and the other blade S is moved away from the eye as is indicated by the arrow symbols of a circle with a dot or a cross,

indicative of the direction of motion along the axis of the eye on each of these elements. In the case of the left hand lay in Figure 9 at station A, the blades are exactly transposed, to cause a relative shearing motion to dispose the flash upwardly and downwardly opposite to that of Figure 8 at station A.

At station E, which corresponds to the bottom of the helices as viewed in Figures 8a and 9a, the shears S, S are presented normal to the axis X of the wire in equal and opposite arrangement, whereby the fins of the lead ends of each are displaced in the direction of the arrows in as shown at station B in Figures 8 and 9, and Figures 8a and 9a.

Station C represents the opposite side of the helix to that of station A, and thus the relationship of the shear parts as between the right and left lay are exactly the reverse of those of station A, already described. Here again with the axis of shear It moving tangentially to the cylinders H within which the axis X of the wires lie causes a drag of metal in the direction of the arrows shown at k in Figures 8-9, 8a-9a, station C, respectively. It will be noted that these are just the opposite with respect to the right and left lays.

At station D in these figures, the top of each helix is being addressed by the shears as viewed in Figures 8a and 9a, and the same conditions obtain wherein the effective elements of the shear blades S, S are moved between parallel planes IT, ET tangent to the internal and external cylinders IC, EC of the helices, and the axis of shear k is tangent to the cylinder H of the axis X of the wire, as is shown. In all cases the axis of shear k is normal to appropriate radii of the helices, and the plane of shear is normal to the axis X of the wire of which the helices are composed.

As shown in Figure 7, which may be regarded as a fragmentary elevational view showing the opposite ends of the helix of Figure 6 in right and left lay embodiments, respectively, the major axis 13a of the cut section of the wire extends tangentially to the wires axis X, and projects to the left (ll) of a right hand lay IDR as regards the lead end, and to the right (tr) of a right hand lay as regards the trailing end. In the case of the left hand lay helix IOL, just the reverse disposition of fin is realized (Zr and tl) over that discussed in the case of IOR, Figure '7.

A special note should be taken of the fact that, if these cut sections of helices shown in Figures 6 and '7 are turned end for end (rotated in the plane of the paper in Figure '7) the same relative condition maintains, as illustrated, with the fins of the then lead ends of the right hand lay helices still extending to the left, and that of the left hand lay helices still extending to the right, and with the trailing ends of each still extending oppositely without change. That is important, since with the helices that are cut in accordance with the conventional practice, illustrated in Figures 1 and 2, the opposite ends of the same cut section are never identical, one always extending interiorly of the internal cylinder of the helix, and the other always extending exteriorly of the external cylinder of the helix, whereupon the inversion of such pieces does not result in an identical condition as regards these projections. Thus, it follows that the internally disposed end of aconventional cut helix is ever present to do damage to the line body of ultimate association, even though the opposite end may be harmlessly disposed outwardly so as to avoid scratching the wire. And, since it is customary to apply armor rods from their centers and proceed to twist them about the line body of association from the center outwardly, the internally projecting end, upon snapping into place, always results in damage to the line body.

In the present invention both of the cut ends of an armor rod are not only disposedtangentially, but, with regard to the lay of the helix, are always disposed so that the fin at each end is in trailing relation to the movement of the armor rod as it is twisted into position upon a line body, and, thus, neither is disposed where it can engage and scarify the line body of association.

As was stated in the forepart of this specification, whenhelices are sheared in accordance with conventional practice, irrespective of the point at which the shear blade initially addresses the helix, the latter will roll or rotate about its axis until the point of engagement with the other of the shear elements is diametrically opposite to the direction of approach of the moving shear element, at which point it is confined between the shear elements in such relation that the axis of shear and a radius of the helix coincide. To give effect to the present invention, it is necessary that adequate provision be made not only to present the helix to the shearing elements in a preferred tangential manner, but securely to hold the helix against rolling and in such proper position so that the shearing may be accomplished with due regard to the following conditions:

1. That the axis of shear be substantially tangent to the cylinder of the axis of the wire;

2. That the plane of shear be normal to the axis of the wire; and

3. That the relative movements of the shearing elements be such as to dispose the drag of the metal in the proper direction with regard to the right hand or left hand lay characteristics of the helix.

The relationship of the shear blades, shown in Figures 8 and 9, is correct to give effect to this result. The right lay of Figures 8 and 8a is a lay, which when viewing the helix in end view from the bottom of Figure 8, the helix shown in Figure 80; will progress from the section of the Wire illustrated therein away from the viewer in a clockwise direction, while that of Figure 9a, being a left lay, will progress away from the viewer in a counterclockwise direction from the section of the wire, as illustrated.

The apparatus shown in Figure 10 is schematically representative of one form of device which can give effect to this invention. Here is shown a supply 2a of straight wire 2! being delivered from a coil through a conventional forming machine 22, the details of which are not shown, but which is capable of imparting a helical set 23 to the wire. The wire comes out of the forming machine in cork screw fashion; that is, with the thread of the helix 23 tracking in the same helical path, screw fashion, until it is addressed by the shear, which is shown at 25 in this figure. In order to make sure that the helix 23 addresses the shear in the proper fashion, as herein described, a suitable guide 30 which may take the form of that shown in Figures 11 to 13, may be provided for this purpose. The guide 3t com prises a hollow cylinder 31 and internal mandrel 32, having a spiral groove 3'3 machined therein, as shown in Figure 12, which groove the pitch as the helix 23, being formed by the forming instrumentali-ty 2-2 schematically shown in Figure 10. The guide 30, in order to accommodate helices of difierent pitch lengths, may be provided with several mandrels 32 having appropriate helical grooves 33 which may be interchanged within the cylinder 3: by releasing and tightening the set screw 34shown in these figures. In addition, since the delivery point of the helices may vary as between the several sizes produced, the guide 31] should be axially adjustable along the axis of the helix, in order that the wire may track and register correctly with the helical groove of the mandrel. This axially adjustable feature is provided by mounting the guide 39 upon an extension 4i] of the shearing device 25 in a slide bearing 4! arranged between the guide and the extension, which is adapted to accommodate a pedestal 42 depending from the sleeve portion 31 of the guide. Axial adjustment may be effected by loosening and setting the nuts 43. These illustrations are schematic and are not a limitation upon the arrangements which may be employed for this purpose.

A mechanical clamp 50 is provided immediately adjacent to the shear, which is disposed as close as possible to the delivery point of the wire from the guide 30. The shear 25 and the clamp 50 are both actuated by a motor 66 and a power transmission device 6! illustrated here as an eocentric, pitman, and crank, with the details of the mechanical relationship omitted. At the appropriate time, however, as a helix 2% has progressed to the point of cut-01f, a limit switch 52, which is axially adjustable along the path of the wire to afford the desired cut length, is engaged by the lead end of the helix to close a circuit, 63, thus to drive the motor through one clamping and shearing cycle, after which the parts are returned to their non-clamp, non-shearing positions and the .feed of the wire continues. Inasmuch, however, as there is unavoidable lag in the operations of clamping and shearing, and since it is highly important to position the helix for shearing in the preferred manner, a solenoid it is provided adjacent to the clamp 562 which, the instant the helix 23 closes the limit switch 82, is energized firmly to grip the wire and to retain it momentarily during the period in which the clamp is becoming eifective. As the clamp engages the wire, the proper relationship of parts is realized and maintained and the shearing operation is eiiectecl instantaneously thereafter.

It will be understood that the shearing operation causes only a slight hesitancy in the axial progress of the helix, and because of this it is unnecessary to arrest the operation of the helix forming machine, which is, therefore, permitted. to run during the shearing operation. This necessitates, however, that a suflicient distance d be provided between the forming instrumentality 22 and the guide'iitl to allow some axial and torsional flexibility in the helix, so that during its moment of arrestation, while the shearing is taking place, the wire may buckle upwardly or downwardly, or in fact be permitted to effect a 360 loop in a unidirectional bend as shown in the broken lines L of Figure 10. This is perfectly feasible, inasmuch as the helix 23 is composed of stifi resilient material and will tend to screw along .its helical path, irrespective of the amount of turns or bends to which it is subjected along its way. There is another reason for providing the distance d between the forming and guiding instrumentalities, which has to do with the case in which the pitch length of helix being formed is not an even multiple of the ultimate cut length,

into which the helices are severed. Such a condition will necessitate an adjustment of the axial placement of the guide 30 in relation to the limit switch, and a possible change of mandrels 32 in order to accommodate the helix of the pitch length and cut length required. This will require some torsional and axial flexibility between the forming and guiding instrumentalities, and the distance therebetween should be such as to permit this type of adjustment. Once the parts are in their proper form and relationship, the helix must always emerge from the guide 35 at exactly the same position, and hence, must pass through the solenoid and mechanical clamp so as to be presented to the shears in the preferred manner without variation.

I claim as my invention:

1. A preformed helical reinforcement for linear bodies cut to length so as to have sheared end sections thereon, said end sections having an eccentricity of mass defining fins resulting from the drag of the section in shear, said fins being oriented in relatively the same direction, so that,

turned end for end, the sheared end sections are substantially identical.

2. An armor rod of predetermined cut length, sheared at both of its ends from a longer length of helically-preformed stock, the sheared end sections of stock extending eccentrically to one side of the stocks axis as a result of the shearing operation, the long axis of each sheared end section of stock lying substantially tangent to a cylinder within which the axis of the helicallypreformed stock lies, said eccentricity of sections extending relatively to the left in a right-hand helix, and relatively to the right in a left-hand helix, with the opposite ends of the armor rod, in either case, being substantially identical.

3. An armor rod formed from helically-preformed wire having sheared ends thereon, said armor rod being characterized by the fact that the plane of the sheared section lies substantially normal to the axis of the wire, and the axis of shear lies substantially tangent to the cylinder within which the wires axis, in helical configuration, lies.

4. The armor rod of claim 3, in which the sheared end sections are projected along the axis of shear in the direction of shear so as to define fins, said fins at each end extending relatively leftwardly of a right-hand helix, and relatively rightwardly of a left-hand helix, constituting substantially identical ends in each rod.

5. The method of forming helical reinforcements which includes shearing helically-preformed stock so that the axis of shear is substantially tangent to the cylinder of the stock's axis.

6. The method of forming helical reinforcements which includes shearing helically-preformed stock so that the axis of shear is substantially tangent to the cylinder of the stocks axis, and so that the plane of shear is substantially normal to the latter.

7. The invention of claim 5, in which the relative displacement of the stock in shear is leftwardly in a right-hand helix, and rightwardly in a left-hand helix.

8. In the art of making armor rods, the improvement which includes advancing helicallypreformed stock past a shearing instrumentality, and intermittently shearing said stock into individual armor rods so that the axis of shear is substantially tangent to the cylinder of the axis of the helical stock, and the plane of shear is essentially normal thereto.

9. The method of forming armor rods in out lengths from helically-preformed wire continuously which includes continuously imparting a helical set to straight wire supplied for this purpose, and intermittently cutting the continuously preformed wire at a distance from the point at which the helical set is imparted thereto so that the included span of preformed wire is free to accommodate itself to the cutting instrumentality by both axial and tortional movements which do not exceed the elastic limit of the wire.

10. Armor rod-forming means comprising a device for imparting a helical set to wire stock; means for severing the wire stock after its helical preformation into cut lengths; said armor rodforming means being characterized by the provision of suitable spacing between the helical setimparting device and severing means as to afford substantial axial and tortional flexibility in the presentment of the preformed wire stock to the severing means.

11. Apparatus for making armor rods comprising a shearing mechanism, a guide for deliving a wire helix to said shearing mechanism in a helical path, so that the same relative portion of the helix is presented to the shearing mechanism at the instant the latter is actuated to cut an armor rod, means for securely holding the wire helix against movement while being sheared, and means instantaneously effective to secure the wire helix pending actuation of said holding means and shearing mechanism.

12. Apparatus for making armor rods comprising a guide for delivering helical stock in a hellcal path, a shear disposed in said helical path constructed and arranged with the axis of shear substantially tangent to the cylinder of the axis of the helical stock, means for intermittently actuating the shear, and means for securely holding the stock during the actuation of the shear.

13. Apparatus for forming helical stock into predetermined cut lengths comprising a forming device for forming straight stock continuously into a helix; a shearing device for cutting the formed stock; the distance between the forming and shearing devices being such as to aiford axial and tortional flexibility of the helix within the elastic limits of the stock; means responsive to the projection of a predetermined length of helix past said shearing device for actuating the latter, said means being adjustable axially of the helix to vary the predetermined cut-length thereof, and means for invariably presenting the same relative portion of the helix to the shearing device to cut the helix in the same relative position, irrespective of the predetermined length of the cut-off section selected.

14. A tube or armoring composed of the armor rods of claim 2, which are fashioned into helices of conforming pitch and lay, and assembled together in coaxial relation.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date Re. 7,063 Preston Apr. 18, 1876 337,513 Moxham Mar. 9, 1886 344,819 Eckerson July 6, 1886 432,741 Spuhl July 22, 1890 511,435 Kehr Dec. 26, 1893 1,503,944 Fraser Aug. 5, 1924 2,202,538 Selquist May 28, 1940 2,414,045 Kitselman et al Jan. 7, 1947 2,489,921 Moore Dec. 6, 1949 

